Thanks for letting me know! The team monitors the reviews on the Store pretty religiously so I"m sure they'll have an update in the works
It's strange that A8 worked without you being signed into Facebook. Based on the way the cloud saving works in our games according to the game teams, players need to be logged into a social account to create a unique ID on our servers. Without this, I was led to believe that it wouldn't actually save progress online. Both A8 and GTR2 use the same methods for cloud saving so this is really baffling.
I'll mention it to the appropriate people and see if the team is aware. What device are you playing on?